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1.
Sci Total Environ ; 654: 1132-1145, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30841388

RESUMO

BACKGROUND: Systematically collected and comparable data on drinking water safety at city-scale is currently unavailable, despite the stated importance of water safety monitoring at scale under the United Nations Sustainable Development Goals (SDGs). We developed a rapid drinking water quality assessment methodology intended to be replicable across all cities and useful for monitoring towards achieving SDG 6 (Clean Water and Sanitation). METHODS: We collected drinking water samples at the point-of-consumption for basic microbial, physical and chemical water quality analysis and conducted household surveys on drinking water, sanitation, and hygiene access from 80 households in the city of Cochabamba over 1 week. We categorized the household's water service level according to the SDG 6 framework. RESULTS: We estimated an average time requirement of 6.4 person-hours and a consumable cost of US $51 per household (n = 80). In this cross-sectional study, 71% of drinking water samples met World Health Organization (WHO) microbiological safety criteria, 96% met WHO chemical quality criteria, and all met WHO aesthetic quality criteria. However, only 18% of the households were categorized as having safely managed drinking water services. None met the criteria for having safely managed sanitation services; nonetheless, 81% had basic sanitation services and 78% had basic hygiene facilities. CONCLUSIONS: This method can generate basic water safety data for a city at a relatively low cost in terms of person-time and materials, yielding useful information for inter-city analyses. Because 29% of samples did not meet microbiological safety criteria, 22% of the households did not have access to handwashing facilities and none had safe sanitation services, we concluded that Cochabamba did not meet normative SDG 6 targets when surveyed. Our study further suggests that water quality at point-of-use more accurately characterizes drinking water safety than infrastructure type.


Assuntos
Água Potável/microbiologia , Monitoramento Ambiental/métodos , Abastecimento de Água/estatística & dados numéricos , Bolívia , Cidades/estatística & dados numéricos , Desinfecção das Mãos , Humanos , Higiene , População Rural , Saneamento , Fatores Socioeconômicos , Qualidade da Água/normas
2.
Chemosphere ; 204: 119-129, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29655104

RESUMO

The treatment of high-strength anaerobic digester effluent in laboratory-scale trickling filters for nitrification and then anaerobic filters for denitrification is reported. Five media types were investigated in the trickling filters: biochar, granular activated carbon (GAC), zeolite, Pall rings, and gravel. Three media were tested in five denitrifying filters: sand (S), bamboo wood chips (B), eucalyptus wood chips (E), bamboo with sand (B+S), and eucalyptus with sand (E+S). The different wood chips served as a supplemental electron donor for denitrification. From six months of operation, biochar, GAC, zeolite, Pall rings, and gravel media had turbidity (NTU) removal efficiencies of 90, 91, 77, 74, and 74%, respectively, and ammonia removal efficiencies of 83, 87, 85, 30, and 80%, respectively, which was primarily by nitrification to nitrate. For the anaerobic filters, S, B, B+S, E, and E+S had nitrate removal efficiencies of 30, 66, 53, 35, and 35%, and turbidity removal efficiencies of 88, 89, 84, 89, and 88%, respectively. Biochar and bamboo were selected as the best combination of media for trickling filter and anaerobic filter sequential treatment. Based on an average initial influent of 600 mg NH3-N L-1, 50 mg NO3-N L-1, and 980 NTU, the biochar filter's effluent would be 97 mg NH3-N L-1, 475 mg NO3-N L-1, and 120 NTU. The bamboo filter's final effluent would be 82 mg NH3-N L-1, 157 mg NO3-N L-1, and 13 NTU, which corresponds to 63% removal of total N and 99% removal of turbidity. These filter media thus present a simple option for sustainable post-treatment for nitrogen management and effluent polishing in low-resources settings.


Assuntos
Desnitrificação , Filtração/métodos , Nitrificação , Nitrogênio/análise , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Reatores Biológicos , Carvão Vegetal
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